One possible method for restoring motion of paralyzed limbs is Functional Electrical Stimulation. FES can be applied in early phase of hemiplegia in order to control the affected leg while walking. FES was shown to be a valuable method for training that likely allows the user to walk later on without assistance. Rehabilitation centres mostly use preprogrammed stimulation patterns empirically obtained and manually triggered. The stimulation pattern and timing need to be set and online adapt to optimize the use of preserved capabilities and lead to symmetrical gait. We present an approach based on three phases. First an optimal control based on individually customized model is used to create the basic reference stimulation pattern for the deficient leg. Secondly, the plant is modeled as a nonlinear oscillator. Finally, the oscillator is triggered from the detection of the gait cycle phase assessed via a sensor placed on the healthy leg.